High capacity package seal, sever, and brick apparatus and method

ABSTRACT

Improved clamp, seal, sever, and brick apparatus for use in form, fill, and seal machines (10) that form a polyfoil tube (22) filled with a product (32) into a plurality of sealed packages (31), preferably aseptic packages. The improved apparatus incorporates a plurality of sealing heads mounted on a continuously advancing structure (200) that transversely clamps, seals, and severs the endlessly advancing tube into packages., and compresses the packages to preform them into about their final rectangular configuration. Induction heating is used to seal the web. The sealing heads include a sealing jaw (220) and an anvil jaw (210) hinged together and adapted to clamp the tube therebetween at predetermined locations as the sealing heads and product filled tubing advance, the locations being adjustable and the sealing and anvil jaws being adjustable to control the colume of product clamped and sealed in each package.

This invention relates to a method and machine for forming an advancingtube filled with a product into packages at high rates of production,particularly to an improved method and apparatus for clamping, sealing,severing, and bricking a web of polyfoil material into aseptic packagescontaining a product.

BACKGROUND OF THE INVENTION

Aseptic packages refer to sealed containers containing a substantiallyuniform predetermined amount of a product made in accordance withcommercial aseptic packaging standards. Commercial aseptic packaginginvolves introducing a sterile product into a sterile container and thenhermetically sealing the container in an environment substantially freeof microorganisms capable of growing in a shelf stable product attemperatures at which the cooled finished product is likely to be storedduring distribution and storage prior to consumption. Hermeticallysealed containers minimize the transmission of any gas or fluid throughthe container package so that there is substantially no biologicaltransmission. Preferably the package is also substantially free of airwhich, if present in significant amounts, could promote undesiredmicrobial growth or, even in the absence of microbial growth, adverselyaffect the taste or color of a product. Typical products are fluentmaterials, specifically, a fluid drink such as milk, fruit juices, andthe like.

The sterile containers commonly comprise a laminated web packagingmaterial preferably having at least one layer of current carryingmaterial such as aluminum foil, an exterior layer of thermoplasticmaterial to become the package interior in contact with the product, andan exterior layer of material for contact with the environment. Thelaminated material, also referred to herein as "polyfoil web", istypically strong enough to stand upright in a somewhat rigid finishedconfiguration to contain the product for shipping and storage, and alsocommonly includes a conventional paperboard structural layer. Productlabeling and registration marks and the like may be printed on thepaperboard layer or the outer thermoplastic layer. In the most preferredembodiment of the invention described below, the polyfoil web to be usedcomprises a laminate of, in order, a layer of low density polyethylene,paper stock, Surlyn®, aluminum foil, Surlyn®, and linear low densitypolyethylene. The low density polyethylene layer could also be a highdensity polyethylene, and the linear low density polyethylene layercould be a low density polyethylene.

The thermoplastic material forming the package interior must be capableof being sealed together to form hermetic seals. Typically, opposingthermoplastic layers are heated to a melting temperature so that theywill fuse together. The thermoplastic and metallic foil layers act inconcert to provide the hermetic barrier for the aseptic package. Themetallic foil layer provides a light and oxygen barrier. The outer layeris commonly a thermoplastic material that can be heated so that thepackage seams and triangular tabs of excess material formed during finalforming or bricking of the packages can be fused or tacked to thepackage sidewalls to form an aesthetically pleasing package.

Such polyfoil laminates may include spaced access means to enable theuser to readily extract the product from the finished package.

Several methods and machines for forming aseptic and non asepticpackages or cartons from paper stock and laminated web materials areknown. These methods and machines generally fall into two categories,blank fed and web fed.

In blank fed machines, the supply of web first is separately formed intocut and scored blanks. The blanks are then fed into the forming sectionof the machine one at a time and erected into containers. Many machinesoperate on several blanks at different stages of construction at a time.For aseptic packaging, the containers are sterilized, filled with asterile product, and hermetically sealed close while in a sterileenvironment.

Some blank fed machines form the blanks into cartons intermittently,performing one assembly operation on the blank or carton at each stationand advancing the blank or carton from station to station. Other blankfed machines operate semi-continuously by continuously advancing theblank to form the container and then intermittently advancing thecontainer to sterilize, fill, and seal the container. One commercialintermittent type blank fed aseptic machine is Combiblok, Model No. CF606A.

In web fed machines, the web is taken directly off the roll of webstock, scored (unless prescored on the roll) and fed into the machine.The machine then folds the web to form a column, seals the longitudinaledge to form a tube, fills the tube with a product, and clamps, seals,and severs the tube to form the packages. The web advance may becontinuous, to gradually manipulate the web into sealed packages, orintermittent, to perform each assembly operation while the web isstationary or while the web is moving between stations.

For aseptic packaging, the web is sterilized and fed into a sterilemachine section, so that the tube is sterile and the package is formed,filled and sealed in a sterile environment. One commercial automaticcontinuous feed aseptic machine is Tetra-Pak Model AB 9. Other knownaseptic machines include International Paper Co.'s, web fed asepticpackage machine, Model SA.

In many of the machines, reciprocating means are used to operate on theweb either when the web or package is stationary, reciprocating intoposition and operation and then reciprocating out of position andoperation when the web or package is advanced, or when the packageadvances, reciprocating with and operating on the package as it movesand then returning to the beginning of its stroke range while the web orpackage is stationary to operate on the following package.

The web fed machines may have one or more reciprocating means whichreciprocate while the web continues to advance or opposing endlesslyrotating means such as wheels or endless linked belts containing aplurality of identical means for sequentially operating on the web asthe web advances at a substantially uniform speed. The present inventionrelates to an improvement in web fed type machines, and is designed tohave a production rate substantially higher than that of presently knownmachines.

The primary problem with the aforementioned forming, filling, andsealing machines is that they are limited in the machine speed and webcontrol required to make aseptic packages at a rate of speed higher thanpresently obtainable in an economically efficient manner. The productionrate of known blank fed designs and machines are limited by the timerequired to erect a blank into a carton, fill the carton, and seal it.Intermittent and continuous web fed machines are limited by the rate atwhich the sealing mechanisms can clamp, seal, and sever the tube intopackages or by the speed of the endlessly advancing linked chains orbelts or rotating wheel on which the sealing mechanisms are mounted, orby the rate of reciprocating action of the sealing means to form eachpackage.

Increasing the speed of continuous web fed machines can cause opposingwheels or belts to oscillate or bounce as the sealing mechanisms come incontact with each other to clamp and seal the package. This increaseswear and decreases the useful life of the sealing mechanisms and couldcause the wheels or belts to vibrate or become misaligned or untrackedso that the sealing mechanisms would not seal accurately. Increasingmachine speed is also limited by the dwell time required for clamping,heating, and cooling the web to form heremetic seals.

Similarly, increasing the frequency of reciprocation of the sealingmeans or other elements to increase the rate of production would alsoincrease the wear and exaggerate any imbalance which could cause such anapparatus to shake itself apart. Adding a second reciprocating devicesealing head to increase the rate has been applied with some success,see, for example, Model AB-9 manufactured by Tetra-Pak. However, thistechnique also suffers from having a limited maximum reciprocation andproduction rates and adds undue mechanical complexity to permit theplural means to reciprocate past each other without interference.

Adding a second or multiple production lines does not solve the problemof increasing the production rate of a single machine. Multipleproduction lines mounted on a single frame may achieve some efficienciesin sharing common elements, but it is effectively the same as two ormultiple machines. The rate of production is not increased, only thevolume. Such machines, e.g, the aforementioned Combiblok machine whichhas two parallel production lines, and other known models which havefour production lines, are unduly bulky, mechanically complicated, andoccupy a substantial amount of floor space. Further, the more commonelements shared by the multiple lines, the more complicated andexpensive the machine becomes, especially if the entire machine must bestopped to fix a problem present in only one of the lines.

A problem with using fixed wheels and opposed endless linked belts isthat the structure required to maintain the sealing mechanisms spacedapart has no reliable means for altering the spacing between the sealingmechanisms to aid in preforming the package into a rectangularconfiguration. This typically requires the use of additional formingmeans. Further, for linked chains or belts, there are inherent timingand orientation problems in aligning the opposing sealing and severingmeans on opposite sides of the web given the mechanical flex inherent inmoving linked chains or belts. The vibrations in the belts as theyadvance may result in misalignment, imperfect seals, and may cause thesevering knife to contact and damage the opposing sealing head.

It is therefore an object of this invention to provide a form, fill, andseal machine with a single relatively slowly rotating structure having aplurality of sealing mechanisms for clamping, sealing, severing, andbricking a continuously advancing web of polyfoil material formed into atube and filled with a fluent product into a plurality of packages.

It is another object of this invention to provide a volume control meansto fix the volume of the tube as it is transversely clamped so that eachpackage contains substantially the same quantity of product.

It is another object to adjust the orientation of the sealing mechanismsas they transversely clamp the tube to aid in controlling the volume ofproduct in each package.

It is another object to selectively adjust the angular orientation ofthe sealing mechanisms on the structure so that adjacent sealingmechanisms move relative to one another to form the packages into aboutwhat will be their final bricked form.

It is a further object to maintain the web transversely clamped for aperiod of time sufficient to form hermetic seals, without over-stressingthe mechanical limitations of the apparatus at high rates of production.

SUMMARY OF THE INVENTION

In order to overcome the problems and inherent limitations oftraditional aseptic form, fill, and seal machines, the present inventionprovides improved methods and apparatus for clamping a continuouslyadvancing tube of polyfoil material filled with a product, controllingthe volume of product in the tube as it is transversely clamped, sealingthe tube transversely, severing the tube transversely, and forming thesevered and sealed tube section into about its finished brickedconfiguration for a period of time, without giving the package its finalshape, thereby preforming the package.

In the preferred embodiment, the method and machine are adapted formaking aseptic packages formed from a continuous web of laminatedmaterial during continuously advancing operation, under microprocessorcontrol.

The present invention provides a plurality of sealing mechanisms mountedon and evenly spaced about a rotating structure for clamping, sealing,severing, and preforming packages from the advancing product filledtube. Each sealing mechanism includes a sealing jaw and an anvil jawpivotally connected together with the jaws being rotatably mounted inthe rotating structure. A means for opening and closing the jaws atpredetermined points along the path of travel of the structure as itrotates is provided. The closing of the jaws effects transverse clampingof the polyfoil tube filled with product. Such clamping compresses thetube and forces the product out from between the opposing inner layersof the polyfoil web.

Immediately before the tube is transversely clamped, the configurationof the tube is adjusted by a volume control means so that the volume ofproduct in the tube to be clamped off is substantially uniform from onepackage to the next. With continued rotation of the structure, theclamped tube is segmentally bent to travel about the periphery of thestructure.

The volume control means preferably comprises a device to guide theadvancing clamped edge of the tube and hold it securely, opposingstructures disposed about the tube which can be moved into position toestablish boundaries against which the product filled tube can expand,and contacting members which compress the tube to aid in controlling thetube configuration and, hence, the volume of product in the tube.

Each sealing jaw contains a sealing means for sealing the polyfoil tubetransversely. Preferably, the sealing means is an induction heatingcoil, disposed in the clamped area transverse to the web, which can beenergized for a period of time to induce a current of appropriatedensity in the current carrying layer of the transversely clampedsection of web proximate to the coil. The induced current heats thecurrent carrying layers resistively, and the inner facing thermoplasticlayers conductively, to cause the thermoplastic to melt, fuse together,and cool into a hermetic seal after the induced current is stopped,while the sealing mechanism is clamped under pressure about the web.

In the preferred embodiment, the induction coil is a secondary inductioncoil and energizing the secondary induction coil in the sealing jawinvolves moving the coil into proximity with a stationary work coil thatis directly connected to a conventional radio-frequency generator, asthe sealing mechanism rotates with the rotating structure. When thetransverse coil is in the effective range of the energized work coil, itwill inductively couple thereto and be energized for the period of timeit is coupled, while the work coil is energized, at a predeterminedpower level. The induction coil in turn induces a current in thepolyfoil material sufficient to seal the web transversely. Radiofrequency current permits using thin current carrying coil conductorsbecause the well known skin depth phenomenon, at radio frequencies,causes the current flowing in the conductor to be concentrated in arelatively thin cross sectional area at the conductor surface.

As the structure continues to rotate, the secondary induction coil willrotate out of the effective range of the field generated by the workcoil, effectively decoupling the sealing jaw coil from the r-fgenerator. The energization times may range from continuous energizationat one or more power levels to very short energy bursts or pulses ofenergy at the same or different power levels, depending upon the web,the coil design, the coupling between the work coil and the secondarysealing jaw coils, the rate of speed of the web, and the power rating ofthe r-f generator used.

Other sealing means could be provided such as sonic welding, dielectricor thermal welding and the like.

Means for controlling and changing the orientation of adjacent sealingmechanisms while clamped to the sealed web are provided so that theleading sealing mechanism, which may be normally biased in an advancedposition relative to a position perpendicular to the surface of thestructure, is rotated to a retarded position while the trailing sealingmechanism is in an advanced orientation so that they are urged towardeach other to compress the package clamped between the adjacentmechanisms against a series of flanges to form or brick the package intowhat will be substantially its ultimate, preferably rectangular,configuration. Then, the lead sealing mechanism can be opened andreturned to its normal position and the trailing mechanism retarded tocompress and brick the following package. In an alternate embodiment,the leading sealing mechanism may be retarded as the trailing mechanismis advanced, relative to normal perpendicular position, to compress andbrick the package. During this bricking operation, the volume controlboundaries retract or are moved so as not to interfere with the brickingflanges.

A severing means in the sealing mechanism is actuated through thetransversely clamped area to sever the package from the tube, eitherbefore, during or after the bricking activity The end result is apreformed package which may be further processed into its ultimate finalconfiguration.

In the preferred embodiment, the rotating structure is a cylindricalwheel. The means for opening and closing the jaws is a first cam leverarm system, and the means for adjusting the orientation of the sealingmeans is a second cam lever arm system. For the volume control means,the guide means is the leading sealing mechanism clamped about the tubeand advancing the tube about the periphery of the cross seal wheel, oneboundary is an extendable retractable plate mounted in the anvil jaw ofthe following sealing mechanism which is about to be closed, and theother boundary is a plurality of fingers projecting from the leadingsealing jaw. The contacting members are oscillating fingers that contactthe tube as the tube advances past a stationary work station. Thetransverse induction coil is preferably mounted in the sealing jaw, andthe severing means is preferably an extendable retractable knife mountedin the anvil jaw. Movement of the knife is controlled by biasing springsand a third cam. After the bricking and severing steps, the sealing andanvil jaws are separated and the preformed package may be taken from therotating wheel to further package forming and handling operations. Theplurality of sealing mechanisms thus form a plurality of preformedpackages as the wheel rotates.

The present invention is particularly useful in machines for formingaseptic packages where a polyfoil web is sterilized, the web is formedinto a continuously advancing tube by folding the web and longitudinallysealing the opposing web edges together, the tube is filled with a coolsterile product and then transversely clamped, sealed, severed, andbricked using the plurality of sealing mechanisms of the presentinvention to preform the sealed package into what will be its finalshape and the preformed aseptic package is squared into a rectangularshape by bricking, and the excess polyfoil packaging material isflattened or tacked against the packages panels to form a finishedaseptic package.

In the preferred embodiment, the polyfoil web is taken off a supply rolland scored or prescored with a pattern of score lines corresponding tothe folds the web will make to form a finished package so that thebricking causes the polyfoil tube to fold at the desired location foreach package.

It is to be understood that while the present invention is discussed inthe context of producing quarter-liter aseptic packages, one skilled inthe art could use the methods and apparatus in other areas including,but not limited to, packages of different sizes and shapes, non-asepticpackages, packages that must be kept refrigerated and packagescontaining fluent particles. Therefore, the foregoing and followingdescription is to be viewed as illustrative and not in a limiting sense.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevated perspective view of an aseptic package forming,filling, sealing, and bricking machine in accordance with the presentinvention.

FIG. 2 is a top sectional view of a polyfoil web corresponding to onepackage, after scoring, for use in accordance with the presentinvention.

FIG. 3 is a cross-sectional view of a conventional scoring unit for theweb of FIG. 2.

FIGS. 3a-3e are cross-sectional views of FIG. 2 taken across respectivelines 3a--3a, 3b--3b, 3c--3c, 3d--3d, and 3e--3e.

FIG. 4 is a sectional schematic view of a primary work coil adapted foruse with the present invention.

FIG. 5 is a face view of a sealing jaw in accordance with the presentinvention.

FIG. 6 is a top sectional view of FIG. 5 taken along line 6--6.

FIG. 7 is a side sectional view of FIG. 5 taken along line 7--7.

FIG. 8 is a side sectional view of FIG. 5 taken along line 8--8.

FIG. 9 is a top view of the transverse induction coil of the sealing jawof FIG. 5.

FIG. 10 is an end view of FIG. 9 taken along line 10--10.

FIG. 11 is a face sectional view of FIG. 10 taken along line 11--11.

FIG. 12 is an end sectional view of FIG. 11 taken along line 12--12.

FIG. 13 is an end sectional view of FIG. 11 taken along line 13--13.

FIG. 14 is a side view of the volume control assembly in accordance withthe present invention.

FIG. 15 is a top sectional view of FIG. 14 taken along line 15--15.

FIG. 16 is a top sectional view of FIG. 14 taken along line 16--16.

FIG. 17 is a rear view of the volume control assembly in accordance withthe present invention.

FIG. 18 is a side sectional view of FIG. 17 taken along line 18--18.

FIG. 19 is an illustrative partial sectional view of FIG. 17.

FIG. 20 is a schematic illustration of the movement of the volumecontrol assembly finger of FIG. 19.

FIG. 21 is a side cross-sectional view of the cross seal wheel inaccordance with the present invention.

FIG. 22 is a timing chart of the operation of a cross seal wheel inaccordance with the present invention.

FIG. 23 is a partial exploded elevated perspective view of FIG. 21.

FIG. 24 is a partial front cross-sectional view of FIG. 23 taken throughthe longitudinal axis.

FIG. 25 is a partial front cross sectional view of the cross seal wheelguide mechanism shown in FIG. 23.

FIG. 26 is a top cross sectional view of FIG. 21 taken along line26--26.

FIGS. 27a and 27b are side sectional views of FIG. 26 taken along line27--27.

FIG. 28 is a front view of FIG. 27b taken along lines 28--28.

FIG. 29 is a top sectional view of the anvil assembly of FIG. 23. FIG.30 is a side sectional view of FIG. 29 taken along line 30--30.

FIG. 31 is a side sectional view of FIG. 29 taken along line 31--31.

FIG. 32 is a side sectional view of FIG. 29 taken along line 32--32.

FIG. 33 is a side sectional view of FIG. 29 taken along line 33--33.

FIG. 34 is a top sectional view of FIG. 21 taken along line 34--34.

FIG. 35 is a rear view of FIG. 29.

FIG. 36 is and end view of FIG. 35 taken along line 36--36.

FIG. 37 is a side sectional view of FIG. 23 taken along line 37--37.

FIG. 38 is a top sectional view of the volume control cam shown in FIG.42.

FIG. 39 is a side sectional view of the segmented cam assembly inaccordance with the present invention.

FIG. 40 is a rear cross sectional view of FIG. 39 taken along lines40--40.

FIG. 41 is a schematic illustration of the movement of the adjacentsealing mechanisms of FIG. 21 during the bricking operation.

FIG. 42 is a face view of the volume control cam in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1, 21, and 23, an illustrative embodiment of thisinvention is useful in connection with form, fill, seal, and brickmachine 10, which may be a microprocessor controlled apparatus thatproduces finished polyfoil packages 31 filled with product 32 by passingpolyfoil web 20 through scoring area 51 (if web 20 is not prescored),passing scored web 20 into a cleaned and preferably presterilized area100 to sterilize web 20, forming web 20 into polyfoil tube 22 invertical seal area 130, filling tube 22 with product 32, passing filledtube 22 into rotating cross seal wheel 200 to transversely clamp, seal,sever, and brick tube 22 into discrete preformed packages 30 which maybe subsequently formed into finished containers 31 for packaging andshipping by forming apparatus 300. The apparatus may be intermittentlyor, preferably, continuously driven in a controlled fashion as known tothose of skill in the art.

As shown in FIGS. 2 and 3, scoring unit 51 imprints conventionally apattern of positive and negative and vertical, horizontal and 45° scorelines into web 20 to facilitate package forming and bricking into finalform, e.g., rectangular package 31 (see FIG. 1). In the preferredembodiment, positive score lines P and negative scorelines N (or maleand female respectively), relative to the foil side view, facilitateproper and uniform folding of the web according to which way the web isscored. A male score will cause the two adjacent panels to form an anglewith the scoreline at the base. The directions of folding are indicatedby the arrows shown in FIG. 3. The male and female score lines do nointersect. This prevents unduly stretching, tearing or delaminating web20, prevents product leakage at intersecting package panels, and permitsforming a substantially rectangular package having a substantially flatbottom.

Web 20 enters sterilization area 100 where it is cleaned (if necessary)and at least the product contacting side of the polyfoil web issterilized. The web is maintained sterile at least until after theproduct containing package is transversely and hermetically sealed.Product 32 is taken from supply 402 e.g. a conventional sterile productprocessor or storage tank, and introduced into continuously forming tube22 by filler tube 400 which terminates well below the product level tominimize the amount of air introduced into product 32.

In accordance with the preferred embodiment, there is always enoughproduct in the tube for several packages. The instantaneous productlevel may be detected by the microprocessor and the rate of fillcontrolled, for example, by a throttling valve, to keep the productlevel within a defined working range, taking into account surging of theproduct level within the working range as package are formed and severedat the end of advancing tube 22. The microprocessor may shut downmachine 10 when predetermined overflow or underflow limits are exceeded.

Sterile air is typically injected inside tube 22 above the product tomaintain aseptic sterility of the product and the product filled tubebefore the tube is sealed transversely.

After web 20 is sterilized, it is fed into tube forming section 130where it is sealed together to form tube 22. Preferably, web 20 isfolded longitudinally with the web edges in opposition, insidethermoplastic layer to inside thermoplastic layer, and filled withproduct 32. Preferably, longitudinal sealing is by induction heating,fusing hermetically the thermoplastic layers together; but alternativesealing means could be used, e.g., heat, sonic, dielectric or thermalwelding or the like. Alternate constructions of tube 22 could includesealing the web edges inside to outside in an overlapping fashion, orsealing together multiple pieces of web or using spirally wound web toform the tube.

Referring to FIGS. 1 and 21-25, the transverse tube clamping, sealing,and severing operation of the present invention is shown. Tube 22,filled with product 32, advances downwardly and approaches the beginningof the seal area at location 201. Cross seal wheel 200 inside housing199 of machine 10 contains a plurality of clamping and sealingmechanisms secured to flanges extending from wheel 200. Cross seal wheel200 is adapted for rotating relative to housing 199, preferably underthe control of the microprocessor, from a drive source (not shown)affixed to the end of spindle 198. Spindle 198 is aligned with the axisof revolution of cross seal wheel 200 and drives cross seal wheel 200.

In the preferred embodiment there are fifteen sealing mechanisms formaking fifteen transverse seals for fifteen complete packages perrevolution, but this number could be changed with corresponding machinedesign changes to accommodate more or fewer sealing mechanisms andpackages per cross seal wheel revolution. Similarly, the cross sealwheel and sealing mechanisms dimensions could be modified to correspondto a particular size package.

Referring to FIGS. 21, 22, 23, and 25, each sealing mechanism includessealing jaw 220 which is rotatably aligned with the central axis ofcross seal wheel 200, and anvil jaw 210 which at one end is pivotablyconnected to cross seal wheel 200 and sealing jaw 220 by compressionspring hinge apparatus 240. The angular orientation of the sealingmechanism can be adjusted, as described below, by adjusting the relativerotation of each sealing jaw about its axis.

Apparatus 240 controls movement of anvil arm 210 between its fully openposition and fully closed position relative to sealing jaw 220. In theopen position, anvil jaw 210 extends from cross seal wheel 200 at anangle of about 70°, as shown in FIG. 1. The angle must be sufficient forthe arm to clear machine 10 apparatus as the arm swings about its path.In the closed position, anvil jaw 210 is held parallel to sealing jaw220 and retained in place either by compression spring hinge apparatus240 alone, or preferably in combination with other means, for example,high pressure cam track 202, mounted on frame 11. Cam track 202 isadapted for urging cam follower 222 towards sealing jaw 220 to providean additional high pressure clamping force (see FIGS. 22, 27a). Camfollower 222 is mounted for rotation on the unhinged end of anvil jaw210 and is adapted for travel along and inside surface 203 of track 202.High pressure cam track 202 extends for a distance along an arc-lengthof about 58 degrees about and spaced from the axis of cross seal wheel200 along the transverse clamping, sealing, and severing area.

During operation, a location on tube 22 is transversely clamped betweenanvil jaw 210 and sealing jaw 220 for the clamping, sealing, andsevering operation as anvil jaw 210 is closed. The transverse sealingarea is defined, with reference to FIG. 2, as comprising panels 40a and42a, respectively above and below scorelines 41 and 43, and the opposingareas when web 20 is folded about score lines 39 (but preferably notfolding panel 39a) during transverse clamping. The force exerted on tube22 by the sealing mechanism must be sufficient to flatten tube 22 sothat substantially all the product is removed from the transverse areato be sealed and the inner thermoplastic layers of tube 22 are incontact for fusion when heated as described below. The pressure istypically about several hundred psi and is controlled by compressionsprings and close mechanical tolerances which accommodate clamping andother motion as cross seal wheel 200 rotates. This ensures an adequateseal and also maintain sufficient pressure to permit passing a cut offknife through the web without dragging any polyfoil through. The springpressure will tolerate a moderate amount of wear and permit satisfactoryoperation until visual inspection reveals replacement or adjustment isrequired.

Referring to FIGS. 23, 29, and 32, compression spring hinge apparatus240 comprises hinge 242, pivot 244, piston 246 and compression spring248. Hinge 242 is pivotally mounted to cross seal wheel 200 at pivot 221on member 500 and contains mounting bracket 502 for connecting hinge 242t anvil jaw 210. Lever 504 is pivotally mounted to hinge 242 at pivot508 which is arranged at a location that can be shifted along a radiusextending from the center of pivot 221. Lever 504 contains boss 219 andarm 510. Arm 510 is mounted so that it extends into yoke 540 (see FIG.32) and has contacting pins 511 and 512. Yoke 540 may be secured tomounting bracket 502 by two bolts. Piston 246 is mounted betweenmounting bracket 502 on compression spring 248 in cylinder 550. Contactpin 512 is disposed towards piston 246. In cross member 541 of yoke 540is adjustable set screw 542. Contact pin 511 is disposed towards setscrew 542.

The other end of lever 504 contains boss 219 which contains pivot 244and is pivotally connected to pushrod 218 which is connected at itsother end to a cammed twin-lever arm fulcrum system.

Referring to FIGS. 23, 25, and 29, the cammed twin lever fulcrum systemcomprises lever arms 214 and 217 connected together at bearing 215 whichis mounted for rotation in flange 216, extending from and about crossseal wheel 200. Cam follower 211 is attached to one of the lever arms,for example, lever arm 214, and is adapted to run in grooved cam 212which, mounted to housing 199, is stationary relative to the rotatingcross seal wheel. Flange 216 is adapted for receiving a plurality ofbearings 215 corresponding to the plurality of sealing mechanisms.

The lever arms transfer the rotational movement of bearing 215 intotranslational movement of pushrod 218 to open and close anvil jaw 210about its pivot point 221. As cam follower 211 moves along the groovedpath, any change in position of cam follower 211 relative to the axis ofbearing 215 will cause a proportionate rotational change in position oflever arm 217 at about the point of connection to pushrod 218.Therefore, the noncircular path of the groove in cam 212 causes leverarm 217 to rotate and thereby causes pushrod 218 to translate in or out.Because pushrod 218 is connected to boss 219 of lever 504 which isconnected to anvil jaw 210 which is hingeably connected to cross sealwheel 200 at pivot 221, movement of pushrod 218 causes anvil jaw 210 toopen and close as cam follower 211 moves relative to bearing 215.

In operation, anvil arm 210 rotates about pivot 221 until contact ismade with sealing jaw 220. Cam follower 211 continues to move the leverarm linkage system in the same direction for a few degrees more, butbecause arm 210 is in contact with jaw 220, the point of pivot changesfrom 221 to 508. Bracket 510 thus pivots about pivot 508, compressinglow pressure spring 248 and ensuring that arm 210 is fully closed andclamping on tube 22 with sufficient pressure to cut off liquid flow. Agap develops between pin 511 nd set screw 542 which allows a slightmovement of arm 210 when compressing high pressure springs 596 (FIG. 6)without exerting a large force on cam follower 211. By adjusting setscrew 542, the relative position of arm 210 can be modified with respectto cam follower 211 by a small amount. This adjustment is made so thatall fifteen anvil arms close at exactly the same nominal angularorientation of the cross seal wheel. This setting is also made incombination with setting the angular orientation of jaw 220 at the timeof closing, in the nominal closing position, to ensure that all fifteenheads fold around equal portions of web 22. Other setting screws adjustthe nominal angular orientation of the sealing mechanism (jaws 210 and220) so that they are all the same. Thus, the fifteen sealing mechanismsare at same angle and close at same time to pick up the same amount ofweb, unless movable cam 534 (FIGS. 37, 40) is moved from the nominalposition as explained below.

In order to accommodate the side to side motion of pushrod 218 as ittranslates back and forth to operate lever 504, pushrod 218 may beprovided with conventional self aligning ball bearing 642 having asufficient range of motion to permit smooth action of lever 504 aspushrod 218 moves side to side and back and forth.

Conventional self aligning ball bearings 648 are provided to operateboss 219 of lever 504 to accommodate any side to side motion of pushrod218 at boss 219.

The hinge assembly for pivots 221 and 508 are shown in FIGS. 29 and 33.Lever arm 504 is secured to pivot shaft 630 by set screw 629. Hinge 242has two flanges 632 and 633 that straddle lever 504 and pivot freelyabout shaft 630. Member 500 has a ring of material extending about shaft636 and has two beveled rings 634 and 635 on its inner diametersubstantially parallel to and spaced from bevels 637 and 638. In betweenbevels 634, 635 and 637, 638 are a plurality of bearings 639 adapted tosimultaneously roll along beveled surfaces 637 and 634 or 638 and 635 sothat member 500 is centered about hinge 242 as it pivots about shaft636. Bearings 639 preferably have a cylindrical or conical crosssection. Means for retaining bearings 639 in place may be provided, forexample, lips or bosses at the extreme edges of bevels 637 and 638 orretaining wires 631, as shown in FIG. 33. Hinge 242 may be bolted toshaft 636 to form pivot 221, by bolts 629.

Referring to FIGS. 21, 22, 23, 29, 31, 35, and 36, anvil jaw 210comprises arm 230, boss 238, head 232, cutting means 234, and cuttingdrive means 236. Arm 230 is an elongated structural support member andmay be made of any material capable of withstanding the forcerequirements of pressing and cutting, for example, reinforced phenolics,nylons, epoxy fiberglass composites, stainless steel, graphite, and thelike. Boss 238 extends from the center of arm 230 and houses cuttingmeans 234 and cutting drive means 236.

Extending along the front surface of arm 230 is head 232 which comprisesparallel anvil surfaces 600 and 601, flange 603 and bolts 604 forsecuring head 232 to boss 238 of arm 230. Anvil surfaces 600 and 601 arespaced apart a distance sufficient to permit passage therebetween ofcutting means 234. Preferably, cutting means 234 is a knife having asharp cutting blade surface (e.g., serrated) capable of severingflattened tube 22, with the blade cutting edge being longer thanflattened tube 22 is wide so as to cut entirely across tube 22 duringthe severing operation. Anvil surfaces 600 and 601 are preferablycomprised of rigid nonconductive reinforced material and duringtransverse clamping are urged into contact with tube 22 in opposition tosealing jaw 220 as anvil jaw 210 is closed by passage of cam follower222 along cam 212. Anvil surfaces 600 and 601 may be coated with anabrasive resistant material to reduce wear, a release material thatpromotes separation of sealed packages 30 after having been severed fromtube 22 as the sealing mechanism opens and anvil jaw 210 separates frompackage 30, or both.

Flange 603 serves as a package preforming surface as described below.Mounted flush in flange 603 is pusher plate 1000 which is connected toshafts 1002 by bolts 1004. Shafts 1002 are adapted to slide axially inbushings 1010 under the control of air drive cylinder 1006 and source ofair pressure 1008. Pusher plate 1000 can be extended out from flange 603to help control the volume of product in tube 22 as tube 22 is clampedoff by the sealing mechanism as described below. Air pressure istypically used to extend plate 1000 under the control of a conventionalslide valve plate (not shown). When one of bushings 1010 is adjacent tothe valve plate, air passes from the end of pipe 1008 therethrough toextend the plate of that sealing mechanism. Extension occurs before thesealing mechanism closes and plate 1000 remains rigidly extended untilafter the mechanism closes. After closing, the sealing mechanism hasadvanced with cross seal wheel 200 so that bushing 1010 is no longeradjacent to the slide valve plate and plate 1000 is thereby cut off frompipe 1008 and its source of air. Consequently, during the bricking orpreforming operation described herein, the compression of package 30between adjacent sealing mechanisms causes plate 1000 to retract to beflush with flange 603. The timing of the extension of pusher plate 1000is shown in FIG. 22.

Anvil surfaces 600 and 601 have a pronounced surface at area 602 thatcorresponds to the configuration of the end surface of sealing jaw 220.The purpose of pronounced area 602 is to interfit with end 582 ofsecondary coil 226 which tapers away from anvil jaw surfaces 600 and 601to urge the longitudinal seal in a folded position for preforming. Byfolding the longitudinal seam towards the package panel, it relievesstress placed on the seam by the preforming operation and preventstearing the web at the point where the edge of the seal is held tightlybetween the sealing and anvil jaws as the package is preformed.

The rear surface of cutting means 234 contains extensions 605 and 606that pass into boss 238 and are connected to shafts 607 and 608,respectively. Shafts 607 and 608 are adapted for movement perpendicularto anvil surfaces 600 and 601, sliding within apertures 609 and 610extending through boss 238 to advance and retract cutting means 234.Shafts 607 and 608 are connected at their non cutting ends to cuttingdrive means 236 by means of threaded ends 611 and 612, respectively.Compression springs 613 and 614 are respectively mounted about shafts607 and 608 between rear surface 618 of boss 238 and cutting drive means236 so that a portion of springs 613 and 614 and shafts 607 and 608 arewithin apertures 615 and 616, respectively, of cutting drive means 236.

Referring to FIGS. 26-29, compression springs 613 and 614 bias cuttingdrive means 236 away from rear surface 618 of boss 238 so that cuttingmeans 234 is normally retracted. Affixed to the rear of cutting drivemeans 236 is contact pin 620. Contact pin 620 is associated with freewheel 622 which, upon contact with pin 620, acts to drive contact pin620 towards anvil arm 210 to compress compression springs 613 and 614and extend cutting means 234 out from between anvil surfaces 600 and601, through tube 22 and into a corresponding recess in sealing jaw 220to sever tube 22. The anvil jaw knife assembly is pivotably connected toarm 230 and flange 238 by post 231. This permits final alignment betweenthe anvil and sealing jaws as they close about tube 22.

Free wheel 622 comprises circular cam 624 fixedly mounted to cylinder625 which is rotatably mounted to pin 626 by means such as ball bearingsillustrated at 628. Pin 626 is rigidly mounted to frame 11 withsufficient support to remain substantially parallel to anvil jaw 210. Inoperation, free wheel 622 is located in the area where the seal is to besevered and aligned with contact pin 620 so that as the sealingmechanism advances along its path and cam follower 222 follows track 202after the transverse seal has been made, contact pin 620 comes intocontact with free wheel 622. As the sealing mechanism continues toadvance, contact pin 620 begins to ride along free wheel 622 whichbegins to rotate and thus causes compression springs 613 and 614 tocompress as cutting means 234 extends. The stroke length and period ofcutting means 234 is thus determined by the radius of curvature of cam624 and the relative interference between cam 624 and contact pin 620.The location of free wheel 622 is thus selected to sever tube 22 at theappropriate location and time as the plurality of sealing mechanisms andcutting means 234 travel about the cross seal wheel periphery andsequentially contact wheel 622. In the preferred embodiment, thesevering step occurs after the tube has been transversely sealed andbefore anvil arm 210 is opened. The severing step occurs while tube 22is clamped between anvil arm 210 and sealing jaw 220 under high pressureto minimize the amount of web pulled into cutting groove 223 duringcutting. The timing and location of the cutting step is preferably asfar downstream of the sealing section as possible before cam follower222 begins to exit high pressure cam 202. This permits maximum sealcooling before, and prevents coating the knife with hot thermoplasticduring, cutting.

Referring to FIGS. 4-12, 21, 24 and 26-29, sealing jaw 220 comprisessupport member 570, secondary induction coil 224, and support membermounting bracket 572 connected to induction coil 224 and member 570.

In the preferred embodiment, secondary induction coil 224 comprises twocurrent carrying faces, circular receiver coil 225 and elongated heatingcoil 226, electrically in series so that the current induced in receivercoil 225 also passes through elongated heating coil 226. Receiver coil225 is preferably designed to maximize the current induced therein asthe coil passes through a fixed electromagnetic field radiated byintermediary induction work coil 761, connected to r-f generator 650.Coil 225 is typically coupled to coil 761 at a distance of about 0.020to 0.030 inches.

In the preferred embodiment, receiver coil 225 comprises a single turnsubstantially circular copper loop mounted in a housing forconcentrating the electromagnetic energy. Any conventional radiofrequency generator could be used as long it is capable of producing thepower required for the sealing operation energy level, preferably in therange from about 3 to 5 kw at about 650 KHz.

Referring to FIG. 4, coil 761 is preferably a multiple loop ovalcylindrical type coil having a long axis large enough to permit inducinga current in coil 225 of secondary coil 224 for a period of timeadequate to heat the metallic layer of web 20 during the time coil 225moves across the face of coil 761. Coil 761 is mounted in housing 762and may be imbedded in nonconductive medium 767, e.g., epoxy, tomaintain the coil configuration rigid. Coil 761 may be hollow and have acoolant circulating therethrough. In an alternate embodiment, coil 761could be a pancake type coil of appropriate dimensions.

The plurality of transverse sealing mechanisms on cross seal wheel 200are arranged so that coil 225 of each secondary induction coil 224 isexposed to the electromagnetic field generated by coil 760 for thenecessary period of time to form each transverse seal.

One advantage of the configuration shown in the Figures is that no meansfor cooling the coil is required. However, other configurationsrequiring cooling may be used, for example, using heat dissipating finsor a cooling fluid circulating through passageways interior to the coil.

Conductive loop 228a (FIG. 10) may be imbedded in dielectric orinsulating material 575 within a channel in rigid support member 576 toprevent coil section 225 from short circuiting, arcing, or physicallyshifting under the electromagnetic forces it is subjected to. Rigidsupport member 576 may be ferrite or other magnetic material toconcentrate the electromagnetic radiation to maximize the currentinduced in coil 225 and to electrically couple the field from primarycoil 760 to conductive loop 228a of coil 225.

Elongated coil 226 is designed with a thin and relatively broad currentcarrying face 227 to generate an electromagnetic field that will inducecurrents in the metallic foil layer of the polyfoil web tube 22 in thearea immediately adjacent face 227 of elongated coil 226. Tube 22 isclamped under high pressure so that product 32 is squeezed from betweenthe clamped web and when the thermoplastic layers are heatedconductively by the currents induced in the metallic foil layers theywill fuse together homogeneously. In the preferred embodiment, elongatedcoil 226 is also a half turn copper loop conductor 228b mounted onflanges 229, covering substantially all of face 227 of elongated coil226. Other current carrying conductors could be used, particularly thosehaving greater wear or deformation resistance such as molybdenum, copperalloys and the like. The current carrying conductor 228b forms anelongated loop around groove 223 which is adapted to receive the cuttingedge of cutting means 234 after it severs tube 22.

Because of the well known skin depth phenomenon, a relatively thin layerof current conductor 228b may be used to distribute the current flowingin the secondary induction coil across the width and length of flattenedtube 22 to form the desired seal area corresponding to face 227. Aconductor material, e.g., oxygen free copper, laid on rigid supportmember 572 (FIG. 8), e.g., reinforced phenolics, epoxy fiberglass,ceramics, or similar substantially nonconducting compositions, may beused. The conductor must be thick enough to satisfactorily conduct thecurrent density required to melt the polyfoil without itself melting orwarping. Abrasive resistant material 573 may cover conductor 228b in arelatively thin coating to prevent wear. Material 573 also may includerelease promoting materials to promote release of the exteriorthermoplastic coating of tube 22 from face 227 after the seal has beenmade. Material 573 also may include a dielectric or insulating materialto prevent secondary induction coil 224 from shorting or arcing duringuse, thereby preventing spot burns on tube 22. Material 573 also mayhave a high thermal conductivity so as to conduct heat away fromelongated coil 226 when not excited, thereby maintaining secondary coil224 cool by conduction. Alternately, material 573 may have a low thermalconductivity to prevent the heat generated by current flowing inconductor 228b from conducting therethrough to soften the outerthermoplastic layer of tube 22, but sufficient to permit conductor 228band coil 226 to cool before being energized during the next cycle.

In the preferred embodiment, receiver coil 225 is oriented at rightangles to elongated coil 226 and rigidly bolted into position by bracket577 and bolts 580. Conductive buss bar 578 connects one end of conductor228a of coil 225 to one end of conductor 228b of coil 226, andconductive buss bar 579 connects the other ends of conductors 228a and228b of coils 225 and 226 together, thus forming the single turnsecondary coil of the preferred embodiment.

Conductor 228b extends past end 582 of elongated coil 226 and around theback side of coil 226. The clamping pressure of bolts screwed into holes571 achieves an electrical connection of the center tap of coil 220 tothe machine frame which is electrically grounded. This prevents currentarc-over to the web during operation. End 582 of elongated coil 226 isbeveled away from face 227 in order to follow the contour of theopposing surface 602 (see FIG. 29) so that the tube will be completelysealed to the edge. Beveled end 582 is adapted to fit within protrusionarea 602 of anvil jaw flanges 600 and 601 to relieve stresses to thevertical seal area and form a good mechanical interface for folding thelongitudinal seam and even distribution of forces along the sealing andclamping area.

Secondary induction coil 224 is mounted to rigid support member ormounting bracket 572 by a plurality of bolts. Mounting bracket 572comprises lower flange 584 having a plurality of fingers 583 and upperflange 585 having a plurality of fingers 581 which are used inpreforming package 30 into a substantially rectangular configuration. Inthe preferred embodiment, one of fingers 583 contains an ejection means586 for blowing a pulse of air out aperture 587 against a side wall ofpackage 30 after it has been severed from tube 22 to eject it from crossseal wheel 200. Fingers 583 and 581 are configured so that fingers 581of the leading sealing mechanism and fingers 583 of the followingsealing mechanism intermesh and can pass through their respective planescorresponding to flanges 585 and 583 without contacting as the sealingmechanisms advance as cross seal wheel 200 rotates. See FIG. 34. Asecond stationary slide valve plate (not shown) adjacent cross sealwheel 200 may be used to cause a pulse of air to be blown out aperture587 in ejection means 586 against the wall of package 30 to eject it.

Referring to FIGS. 5, 6, and 26, bracket 572 is mounted on support 570by a suspension means comprising guide shafts 592 and resilient means593. Guide shafts 592 pass through bushings 592a, are bolted to supportmember 570 by nuts 591 and pass through support member 570 intocorresponding cylinders in bracket 572. Each resilient means 593 ismounted in support 570 and comprises piston 594 mounted in cylinder 595on compression spring 596. It provides a high pressure deflection meansfor controlling pressure so that as anvil jaw 210 and sealing jaw 220are closed to compress tube 22 flatly, secondary coil 224 and itsmounting bracket 572 will contact resilient means 593 and must overcomethe force provided by spring 596 before bracket 572 will move the smalldistance towards rigid support 570. A small gap exists, e.g., about 1/8inch, for passing, for example, a double thickness of web 20 or a websplice, without jamming the apparatus. In the preferred embodiment, tworesilient means 593 are shown spaced apart about the expected height ofa finished package 31. Having more than one resilient means provides fora relatively even distribution and absorption of the forces resultingfrom closing anvil jaw 210 and sealing jaw 220. The spacing alsoprovides for better control of the transverse sealing and severingoperation and reduces wear on the sealing mechanism. Resilient means 593work in cooperation with pivot 231 which allows both faces of anvil jaw210 and sealing jaw 220 to remain parallel while the high pressureclamping forces are evenly distributed along the web. The combinationalso provides for rotation of the sealing mechanism. Further, as thehigh pressure spring is set, the angle of anvil jaw 210 about pivot 231will change to keep the jaws parallel and maintain equal pressure alongthe web.

Rigid support 570 is secured to cross seal wheel 200 at its respectiveends by means of conventional rotatably mounted roller bearings 597 and598 in flanges 567 and 568 of cross seal wheel 200. Flanges 567 and 568are similar to flange 216 (FIG. 23) in that they have a plurality ofapertures spaced around cross seal wheel 200 adapted for receiving aplurality of sealing jaws 220 of construction identical to the jawdescribed above.

Also mounted on support member 570 and underneath housing cap 560 are apair of side members 562 arranged in opposition and capable of beingrotated about their respective shafts 564 secured between housing cap560 and member 570. Side members 562 are adapted for pressing inopposing top and bottom of package 30 during the bricking operation.Shafts 564 are mounted for rotation by means of roller bearings 565.

Side members 562 comprise L-shaped structure 561 affixed to one end ofshaft 564 having a substantially flat pressing surface 563 of a surfacearea somewhat less than the surface area of the top or bottom panel of afinished brick 31. Mounted on the lower leg of each L-shaped structure561 is cam follower 566 which is adapted to follow respective opposingfixed cams 559 for causing pressing face 563 to rotate about shaft 564into contact with package 30 to brick package 30. Spring 557 connectedat one end to post 558 on rigid member 570 and at the other end to post556 secured to the bottom of L-shaped structure 561 biases L-shapedstructure 561 in the open position, with presser face 563 away from andnot in contact with tube 22.

Cam 559 has a controlled cam profile to simultaneously close the sidemembers in a timed relationship with the rest of the bricking operationso that the package is bricked substantially simultaneously. Referringto FIG. 22, the side forming cam is moved into the bricking positionwhen the adjacent sealing mechanisms are in the fully bricked position.The bricking operation preferably occurs after the transverse seal ismade and after the package has been severed. The action of cam followers566 and cams 559 overcome the forces of springs 557 to close sidemembers 562. Stops 555, in conjunction with springs 557, serve to limitthe extreme open position of side members 562 and to prevent sidemembers 562 from moving while not in use. See FIG. 5. In otherembodiments, the bricking operation could be performed before thesevering operation and even before the sealing operation, once advancingtube 22 has been securely clamped.

Referring to FIGS. 5, 6, 23, and 26, anvil jaw 210 is securely connectedto sealing jaw 220 to form a single sealing mechanism. Bolts 499extending through rigid member 570 extend into member 500 to secure itsmembers together so that anvil jaw 210 and sealing jaw 220 are in thesame plane relative to each other. Further, cutting means 234 of anviljaw 210 will extend into gap 223 of sealing jaw 210 when the jaws areclosed, to sever flattened tube 22.

Referring to FIGS. 23, 24, 37, and 38, the angular orientation of thesealing mechanism is controlled by a cammed lever-pivot system. Theangular orientation is defined as the angle between the plane in whichanvil jaw 210 will move relative to sealing jaw 220 and the radial planebetween the axis of cross seal wheel 200 and the center longitudinalaxis of rigid member 570 mounted on the periphery of, and at a distancefrom the axis of cross seal wheel 200. The angular orientation pivotsabout the axis of rigid member 570 of sealing jaw 220.

The cammed lever-pivot system comprises lever arm 520, bearing 522, andshaft connectors 524. Shaft connector 524 comprises first unit 525connected to the end of rigid member 570 on the side of flange 567 nothaving secondary induction coil 224, and second unit 526 connected toshaft 527 running through the axis of bearing 522. First unit 525 andsecond unit 526 are connected together so that their axes are alignedand will rotate as one shaft, thereby altering the orientation of rigidmember 570 and the transverse clamping and sealing mechanism as shaft527 rotates. Bearing 522 is mounted for rotation in flange 528, which isperpendicular to the axis of cross seal wheel 200, and adapted to hold aplurality of bearings 522 corresponding to each of the sealingmechanisms. Lever arm 520 is connected to the side of bearing 522opposite shaft connector 524 and extends from bearing shaft 527 at anangle so that rotation of shaft 527 about its longitudinal axis wouldcause the end of lever arm 520 to trace a circle. Cam follower 529 isrotatably mounted at the end of lever arm 520 and is adapted to travelin cam groove 530 of cam 532.

Cam groove 530 thus controls the position of lever arm 520 relative tothe axis of shaft 527 and thereby controls the orientation of thesealing mechanisms.

As cam follower 529 runs along cam groove 530, its angular positionrelative to the axis of shaft 527 may change at predetermined locationsalong the groove so that the plane of orientation of the anvil andsealing jaw, relative to a given radius, shifts. In the preferredembodiment, cam 532 is designed so that after the tube has beentransversely sealed and severed, package 30 undergoes the previouslymentioned bricking designed to crease the scorelines in package 30 bysubstantially forming package 30 into its final shape temporarily,without necessarily leaving package 30 in its final desired shape, e.g.,rectangular brick 31.

To accomplish the bricking operation, cam groove 530 is cut so that camfollowers 529 of adjacent sealing mechanisms rotate about theirrespective bearing shafts 527 and so that at least of of the sealingmechanisms deflects from its normal orientation and the adjacent pair ofsealing mechanisms act in concert to compress package 30 against flanges603, 584, opposing side member surfaces 563, and the top of the leadinganvil and sealing jaws and the bottom of the following anvil and sealingjaws in their closed position. Thus, package 30 is urged into asubstantially rectangular configuration defined by the aforementionedboundaries. In the preferred embodiment, during package compression theflanges are configured to provide 100% closure, i.e., the finalrectangular shape with all of the opposing sides in parallel andperpendicular to the other sides. The cavity size formed by the flangesis preferably slightly less than the intended size of finished package31, e.g., 97% of the finished package volume or size.

When the bricking operation is complete and package 30 has beenpreformed, cam groove 530 returns cam follower 529 to its normal angularposition. Similarly, side members 562 retract and preformed package 30is retained on flange 584 by wire guide means (not shown).

As illustrated in FIGS. 21 and 42, cam groove 530 is designed tomaintain the normal angular position of a given sealing mechanism in anadvanced orientation so that the angular orientation is forward of aradial plane, then to retard the angular orientation behind the radialplane relative to the normal position, so as to aid in bricking thepackage following that sealing mechanism against the next followingsealing mechanism in its normal position. The leading sealing mechanismis then advanced to return it to its normal position, still graspingpreformed package 30. As the sealing mechanism returns to its normalorientation, anvil jaw 210 opens and package 30 is held e.g., by the useof fixed guide rails 590 until transferred to transfer conveyor 280, asillustrated in FIGS. 21, 27b, 28, and 37. In FIG. 37, the maximum degreeof angular advance is shown as angle b and the degree of angular retardis shown as angle a, both preferably about 12° as compared to the 0°radial orientation. Setting angle a equal to angle b provides for 100%closure of the package on all six sides. The degree of advance andretard may vary for different sized packages. In an alternateembodiment, cam 530 could maintain the sealing mechanism in a radialorientation and then simultaneously advance the trailing mechanism whileretarding the leading mechanism to compress package 30 between theadjacent sealing mechanisms. Other variations within the mechanicaltolerance of web 20 could also be applied.

Referring to FIGS. 37-42, movable cam 534 and its control system isshown. The movable cam system controls the pitch or angular orientationof the sealing mechanism as anvil jaw 210 is closed to press tube 22flat against sealing jaw 220. This occurs as tube 22 is segmentally bentabout the periphery of cross seal wheel 200, and may be used to aid incontrolling the volume of product within the tube as the tube is clampedtransversely.

The change in angular orientation relative to the nominal radialorientation adjusts the precise placement of anvil jaw 210 along tube22. Given the substantially constant speed of cross seal wheel 200, face227 of sealing jaw 220 moves at a tangential speed slightly less thanthe velocity of tube 22 as it comes in contact with descending tube 22.The relative difference in speed accounts for the web taken up by thebulging of the package as it is clamped, sealed and preformed. When tube22 is pinched, it is restrained by the sealing mechanisms and deviatesfrom its generally downward path to follow the curve traced by crossseal wheel 200 for the arc length defining the transverse clamping,sealing, cutting, and bricking section. As the tube begins to travelaround the contour of cross seal wheel 200 after the preceding packageis clamped, it causes the sides of tube 22 to compress as the followingsealing jaw contacts tube 22 which makes tube 22 thinner and therebyreduces the cross sectional area and the corresponding volume of product32 in that portion of the advancing tube. Thus, by controlling whereabout the periphery of wheel 200 the sealing mechanism will clamp theend of tube 22 to form the next package 30, the volume of product 32 inthat tube end can be controlled or adjusted.

Cam section 534 is capable of being moved forward or back along an arclength in cam groove 530 by servo stepping motor 535. In the preferredembodiment, the surface of cam 534 affects the angular orientation ofcam follower 529 as it runs along groove 530 which advances (or retards)the sealing mechanism as anvil arm 210 clamps securely across tube 22.Thus, by moving cam segment 534 along cam groove 530, the location oftransverse closure can be selected within the range defined by the arclength the cam can move along.

Cam section 534 is secured to boss 538 of plate 536 which is rotatablymounted about the axis of cross seal wheel 200 by means of preloadedball bearings 537. Preloaded bearings 537 minimize shifts in camalignment as cam section 534 is periodically loaded and unloaded. Plate536 has second boss 531 at the end of which is a housing having ballscrew 533 with interior threads along the inner cylinder walls. Threadedpost 543 is mounted inside ball screw 533 so that as threaded post 543rotates, cylinder 533 moves relative to post 543.

The rotation of threaded post 543 is controlled by stepping motor 535through drive belt 544, pulley 545, and universal joints 546. Pulley 545is fixed in frame 11 so that it rotates but does not move axially.Consequently, threaded post 543 rotates without moving axially asstepping motor 535 rotates. Because plate 536 is adapted to rotate aboutthe axis of cross seal wheel 200, when threaded post 543 rotates theresult is movement of cylinder 533, plate 536, and movable cam section534. Universal joints 546 permit threaded post 543 to bend relative tothe axis of pulley 545 as cylinder 533 moves along its radius as plate536 rotates. Stop sensor means 549 and contacts 547 and 548 on plate 532are disposed to cause motor 535 to stop advancing when movable camsection 534 is already at the extreme end of its predetermined range oftravel. Contacts 547 and 548 may be conventional limit switches.

In the preferred embodiment, once the cam position is selected for agiven web and product under operating conditions, it is typically leftin the same position throughout the production run. In situations wherea machine is dedicated to producing a single size product, once theproper dimensions and closure point are determined, the movable camsegment may be fixed in place or omitted entirely. However, inappropriate circumstances, cam 534 may be dynamically adjusted asnecessary to control the volume of product 32 in package 30 withouthaving to halt production.

Transfer conveyor 280 is shown in FIGS. 1 and 21 to receive packages 30from cross seal wheel 200 after they have been preformed for transfer tofurther processing apparatus not forming a part of this invention toform the finished product.

Referring to FIGS. 1, 2, 15, 20, and 21, immediately before tube 22 isclamped transversely, a pair of volume control fingers 360a and 360bcontact the opposing sides of tube 22 along top package panel 39a andthe bottom of the package comprising panels 46a and 46b (longitudinallysealed together at web ends 24 and 26). Volume control fingers 360a and360b contact tube 22 to push on panels 39a, 46a, and 46b, changing theamount of product 32 in tube 22 by or to a predetermined amount. Byvarying the amount of push, the package volume can be adjusted within apreselected range. Tube 22 then is transversely clamped at the trailingportion of what will become package 30, having previously been clampedat the leading portion of the package by the preceding sealingmechanism, thereby fixing the volume of product 32 in tube 22 insideaseptic package 30 at its preselected volume.

This contact also initiates bending of tube 22, for example, along oneor more of the preselected score lines, e.g., lines labeled A in FIG. 2,by compressing tube 22 adjacent the area of contact, facilitatingsubsequent package forming and bricking along the desired score lines.

The pair of fingers 360 have an oscillatory reciprocating motion movingin three dimensions, (i) towards tube 22 so that tips 361a and 361bextend past and straddle tube 22 (see FIGS. 15, 20), (ii) downwardly andtowards each other, compressing tube 22 inwardly to fix the volume (seeFIG. 20 in stepped positions), and (iii) withdrawing from each other andaway from tube 22 and returning to a starting position to again contacttube 22 at the following location appropriate for contacting thesuccessive packages. Tube 22 is later sealed at each transverse clamping(as described herein), forming the trailing edge of the precedingpackage and the leading edge of the next package to be formed. In thepreferred embodiment, these edges become the side seams of a finishedpackage. Fingers 360a and 360b may move downwardly at the same linearspeed as tube 22, or may move at a faster or slower rate. Relativeslippage will provide for contacting and bending more of the surfacearea of tube 22, if desired.

Referring to FIGS. 14-21, volume control fingers 360a and 360b arerespectively screwed into mountings attached to the end of shafts 365aand 365b. For discussion purposes, only one volume control fingerassembly will be discussed unless otherwise indicated by the suffixes aand b, although it is to be understood that the paired assemblies arecomplementary and arranged in opposition.

Shaft 365 is slidebly engaged in a bracket on subframe 370 whichsubstantially confines movement of shaft 365, relative to subframe 370,to linear motion towards and away from tube 22. Four bearings 371facilitate smooth translation of shaft 365 which is mechanicallycontrolled by the rotation of cam 374.

At the end of shaft 365, opposite to finger 360, is bracket 378 thatcooperates with bracket 379 attached to shaft 380. Brackets 378 and 379are interconnected to comprise a universal joint. At the end of shaft380, opposite to bracket 379 is bracket 381 which is interconnected tobracket 382, forming a second universal joint. Bracket 382 is connectedto one end of arm 385 by means of threaded post 383 and adjustment nut384 which may be rotated to adjust the effective length of threaded bolt383 and the position of finger 360 relative to tube 22. Arm 385 ispivotally connected at pivot 387 to arm 388 mounted on frame 11 and hasat its other end cam follower 390 which is located in groove 375 of cam374. As cam 374 rotates, cam follower 390 will follow cam groove 375 andthus cause arm 385 to rotate about pivot 378 and slide shaft 365 towardsand away from tube 22. The universal joints formed by brackets 378, 379,381, and 382 permit smooth movement of shaft 365 as arm 385 oscillatesand as subframe 370 is shifted perpendicular to the motion of arm 385 asdiscussed below. (Arm 385 preferably actuates both shafts 365a and 365band fingers 360a and 360b in phase simultaneously.) Rotation of arm 385to about its full inward displacement is shown in phantom lines in FIG.14. Cam 374 is fixedly mounted to shaft 373 which is, in turn, rotatablymounted in frame 11 and driven by the machine motor.

Subframes 370a and 370b are adapted for movement in two directions sothat the brackets through which shafts 365a and 365b reciprocate move inan elliptical path. Referring to FIGS. 19 and 20, the elliptical path iscontrolled by the addition of circular motion about two differenteccentrics arranged in high phase. The angle of the ellipse may beadjusted by controlling the additive configurations of the eccentrics.The center to center spacing of the elliptical paths may be adjusted byturning shaft 408 and 409 (FIG. 17) which screws or unscrew threads 440into threaded boss 442 and changes the center to center distance.

Eccentric 356 is mounted on shaft 355 and rotates about shaft 355.Eccentric 356 is mounted for circular rotation in housing 358 so thathousing 358 also moves about shaft 355, although it does not rotate.Similarly, eccentric 357 is mounted on shaft 391 for circular rotationin housing 359 so that as shaft 391 rotates, housing 359 moves aboutshaft 391 without rotating. Housing 359 is secured to subframe 370 sothat the circular, but nonrotating, motion of housing 359 is imparted tosubframe 370. Housing 358 is slidably connected to post 372 on a linearbearing and post 372 is securely fastened to subframe 370 at a pointremote from housing 359. As shaft 355 rotates, the circular non-rotatingmotion of housing 358 causes housing 358 to both slide along post 372and move post 372 in a direction towards and away from rotating shaft355 (like a cam moves a pushrod).

The length of post 372 along which housing 358 moves axially must belong enough to absorb the relative differences in center to centerdistances between shaft 355 and eccentric 356 and shaft 391 andeccentric 357. The differences in center to center and diameters orcurvature of the eccentrics determines both the shape of the ellipticalpath and the angle of the elliptical path, i.e., the angle formedbetween the major (or minor) axes of the ellipse and the perpendiculartube. A sequence of 23 positions of shaft 365b is illustrated in FIG. 20showing the positions numbered 20-23, 0, and 1-3 as where, in thepreferred embodiment, finger 360b contacts tube 22 as tube 22 advancesand finger 360b advances in its elliptical path.

Shafts 391a and 391b and 355a and 355b are driven from bevel gears 407and 406 which drive gears 393a and 393b which turn shafts 391a and 391b.At the other end of shafts 391a and 391b, away from gears 393a and 393b,are gears 394, 397, and 405 (a and b respectively) mounted in alignmentfor rotation in frame 369 and arranged so that gears 394 and 405 rotatein the same direction. Thus, shaft 355a is connected to gear 405a androtates in the same direction as shaft 391a. Gears 393a and 393b andtheir respective elements are arranged with opposite rotations toprovide mirror image substantially identical elliptical paths forfingers 360a and 360b in the brackets of subframe 370 for contactingtube 22. The combination of the elliptical motion and the reciprocatingmotion provides the three dimensional movement of fingers 360a and 360bto contact tube 22 and help fix the volume of product captured in tube22 between adjacent sealing mechanisms.

One advantage of the present invention is that it is capable ofmanipulating the polyfoil web at high rates of speed to form uniformlyfilled packages. Specifically, the invention controls the volume ofproduct in the tube as the tube is transversely clamped and segmentallybent while the tube is continuously advanced and filled with product.

The primary volume control apparatus incorporates the volume controlfingers and the pusher plate. Volume control fingers 360a and 360bcontact the tube at right angles to the transverse clampings of thesealing mechanisms, at a location between adjacent sealing mechanisms.This contact tends to reduce the size of the tube and decrease thevolume. In order to fix how far open the tube is spread near the area ofcontact, and how much product is in the tube section to be clamped off,pusher plate 1000 from the sealing mechanism about to be closed, andfingers 581 of upper flange 583 of mounting bracket 572 of the precedingsealing mechanism, are arranged on opposite sides of tube 22 oriented atright angles to volume control fingers 360. Pusher plate 1000 isactivated by air cylinder 1006 and air source 1008 to extend from flange603 to a position where it will contact and thus confine the motion and,hence, the volume of tube 22 as the sealing mechanism closestransversely. Fingers 581, affixed to the preceding sealing mechanism,each have beveled face 1012 as shown in FIG. 8. Thus, as the precedingsealing mechanism continues to advance, fingers 581 rotate about theaxis of the sealing mechanism towards tube 22, and contact tube 22,preferably so that face 1012 is roughly parallel to plate 1000, toconfine the movement of and, hence, the volume of tube 22 as thetrailing sealing mechanism closes. This cooperative effect is shown inFIGS. 21 and 34.

As discussed, movable cam 534 also may be used in controlling volume byselecting where along tube 22 the sealing mechanism transversely clampsthe tube. This clamping location affects the volume because thepreceding, sealing mechanism, having already clamped tube 22, causes theleading edge of tube 22 to deviate from its downward linear path as theleading edge advances about the periphery of cross seal wheel 200. Thischange of direction alters the tube cross sectional configuration andalters the volume. Consequently, depending upon where along tube 22 thefollowing sealing mechanism clamps tube 22, the volume may be adjusted.

Once the volume is fixed, and tube 22 is transversely clamped, airsupply 1008 is closed and pusher plate 1000 can be pressed back flushinto flange 603 by clamped package 30 during the bricking operation asthe orientation of the leading sealing mechanism retards to presspackage 30 against the flanges to its rectangular brick shape. As theleading sealing mechanism retards, fingers 581 now rotate away frompackage 30, and pass by fingers 583 of flange 584 of the followingsealing mechanism. The action of fingers 581 during the brickingoperation are shown schematically in FIG. 41 where the leading sealingmechanism, shown by anvil surface 600a and secondary induction coil 224ais rotated α degrees towards the trailing sealing mechanism shown byflanges 603b, anvil surface 601b, secondary induction coil 224b flange584. Seven steps are shown, numbered 1-7.

We claim:
 1. Apparatus for use in a machine for forming a plurality ofsealed packages from an advancing tube of polyfoil web filled with aproduct, comprising:a structure mounted in the machine and adapted torotate about an axis at a controllable speed; a plurality of sealingmechanisms mounted in a spaced apart relationship about the periphery ofthe structure, each sealing mechanism further comprisinga sealing jawand an anvil jaw pivotably connected together so that one of the sealingor anvil jaws is mounted parallel to the axis of the structure, thesealing mechanism having an open position and a closed position, theclosed position having the anvil and sealing jaws being transverselyclamped together in parallel about the tube to form a clamped package,means for sealing the tube area clamped between the sealing jaw andanvil jaw to form a sealed package, means for severing the transverseseal area, and a plurality of flanges; means for closing each sealingmechanism as it approaches a preselected location in its path of travel,the location being proximate to the advancing tube so that closing thesealing mechanism transversely compresses the tube flat between thesealing jaw and anvil jaw; and means for preforming sealed packagesclamped between adjacent sealing mechanisms by compressing the clampedsealed package against the boundary created by the flanges of theadjacent sealing mechanisms.
 2. The apparatus of claim 1 wherein thestructure is a cylindrical wheel having parallel flanges adapted forreceiving the plurality of sealing mechanisms.
 3. The apparatus of claim1 wherein the means for severing the sealed tube area further comprisesa knife mounted in the anvil jaw having a retracted position within theanvil jaw and an extended position sufficient to pass the knife throughthe sealed tube area.
 4. The apparatus of claim 1 further comprising avolume control means for controlling the tube configuration and thevolume of product in the tube before the tube is transversely clamped toform a clamped package.
 5. The apparatus of claim 4 wherein the volumecontrol means further comprises means for controlling the orientation ofeach sealing mechanism as it closes about the tube at the predeterminedlocation to control the volume of product in each clamped package. 6.The apparatus of claim 4 wherein the volume control means furthercomprises a contacting means for contacting the polyfoil tube to adjustthe tube configuration before the tube is transversely clamped tocontrol the volume of product in the tube proximate to the point ofcontact before the tube is transversely clamped.
 7. The apparatus ofclaim 6 wherein the contacting means further comprises a pair of fingersoriented to trace elliptical paths having substantially the same majorand minor axis and oriented in opposition, moving in opposite rotationsand at an angle to each other, so that the fingers contact the polyfoiltube on opposite sides while moving in the same direction at about thesame speed.
 8. The apparatus of claim 4 wherein the volume control meansfurther comprises, for each sealing mechanism, a pressing surfaceextending from the jaw mounted parallel to the axis of rotation, and apusher plate mounted in a preforming flange on the other jaw, the pusherplate having an extended position for controlling the volume of productin the tube and a retracted position for preforming the tube, and saidpresser plate and flange cooperate as the sealing mechanism is closingto confine the tube to a predetermined configuration as the tube istransversely clamped to control the volume of product in the tube. 9.The apparatus of claim 8 wherein the pressing surface of one jaw of asealing mechanism and the pusher plate of the other jaw and the adjacentand trailing sealing mechanism cooperate as the trailing sealingmechanism is closing to confine the tube to a predeterminedconfiguration as the tube is transversely clamped to control the volumeof product in the tube.
 10. The apparatus of claim 1 wherein the sealingmeans further comprises a secondary induction coil mounted in thesealing jaw, the coil being adapted to respond to a firstelectromagnetic field as said coil passes therethrough and therebygenerate a second electromagnetic field to induce a current in thepolyfoil tube to heat and seal the transversely clamped tube area. 11.The apparatus of claim 1 wherein the means for preforming packagesfurther comprises means for altering the relative orientation ofadjacent sealing mechanisms to compress a clamped package against theplurality flanges to conform the package into a configuration bounded bythe flanges.
 12. The apparatus of claim 2 wherein one of the sealing jawor anvil jaw is mounted in the cylindrical flanges of the rotating wheeland is rotatable about a jaw axis, and the apparatus further comprises:alever arm secured to one end of the rotatably mounted jaw; a first fixedcam, mounted in the machine, having a first cam groove; and a first camfollower adapted for running in the first cam groove and secured to theend of the lever arm so that the location of the first cam followerrelative to the jaw axis as determined by the first cam groovedetermines the orientation of the rotatably mounted jaw and the sealingmechanism.
 13. The apparatus of claim 12 wherein the means forpreforming packages further comprises first and second path segments inthe first cam groove for positioning the first cam follower inpreselected locations and the sealing mechanisms in correspondingpreselected orientations relative to the jaw axis,the first path segmentbeing configured to place a sealing mechanism in an advanced angularorientation, the angular orientation of the sealing mechanism being theplane in which the sealing jaw and anvil jaw move relative to each otherand in which the severing means would move, an advanced orientationbeing the outermost portion of the sealing mechanism plane traveling infront of where it would the if the plane extended through the axis ofthe rotating wheel, the second path segment being configured to have theposition of the first cam follower relative to the jaw axis to changethe orientation of a sealing mechanism from an advanced to a retardedorientation, the retarded orientation being the outermost portion of thesealing mechanism plane traveling behind where it would be if the planeextended through the axis of the rotating wheel, the length andorientation of the first and second path segments being selected so thatthe first cam follower associated with the leading sealing mechanismrunning from the first to the second path segments changes the sealingmechanism orientation to a retarded orientation while the first camfollower associated with the trailing sealing mechanism running in thefirst path segment provides the trailing sealing mechanism with anadvanced orientation so that the package clamped between the adjacentsealing mechanisms is compressed against the flanges of the sealingmechanisms for a period of time sufficient to preform the package. 14.The apparatus of claim 13 wherein the first cam groove further comprisesa third path segment following the second path segment in sequence andconfigured to advance the retarded orientation of the leading sealingmechanism to a rest orientation, the rest orientation being sufficientto permit transfer of the preformed package from the rotating wheel. 15.The apparatus of claim 14 wherein the first cam groove furthercomprises:a fourth path segment disposed prior in sequence to the firstpath segment; a movable cam segment located in the fourth path segmenthaving a plurality of positions between a front position and a rearposition, including a nominal position between the front and rearpositions, the front position corresponding to one of a predeterminedrelative maximum advance or relative maximum retard in angularorientation, the rear position of the movable cam segment correspondingto the other of the relative maximum advance or retard in orientation,the nominal position corresponding to the nominal clamping position; anda means for moving the movable cam segment to one of the plurality oflocations to configure the fourth path segment to control the angularorientation of the sealing mechanism as it closes about the tubedepending upon the location of the movable cam segment between its frontand rear positions so that movement of the moveable cam from the nominalposition to either the front or rear position gradually increases thechange in angular orientation from the nominal orientation to therelative maximum advance or retard orientation.
 16. The apparatus ofclaim 2 further comprising:a cam mounted in the machine having a camgroove in a predetermined path about the axis of revolution of thewheel; and, for each sealing mechanism, a cam follower adapted forrunning in the cam groove; a linked lever arm and pushrod means forinterconnecting the cam follower and the pivot of the sealing mechanismso that the linked lever arm and pushrod means causes the sealingmechanism to open and close the anvil and sealing jaws as the camfollower moves either towards or away from the axis of the wheel as thecam follower advances along the cam groove, thereby controlling therelative locations of the anvil and sealing jaw.
 17. A method forforming a plurality of sealed packages from an advancing tube of filledpolyfoil material for use in a form, fill, and seal machine, includingthe steps comprising:advancing the polyfoil tube filled with product;rotating a structure, said structure having a plurality of sealingmechanisms peripherally mounted thereon in a spaced apart relationship,each sealing mechanism comprising a sealing jaw and an anvil jawpivotably connected together so that one of the sealing or anvil jaws ismounted on the structure transversely to the tube, each sealingmechanism having an open position and a closed position, the closedposition having the anvil and sealing jaws being transversely clamped inparallel about the tube; closing the sealing mechanisms at apredetermined location so that the tube is sequentially transverselyclamped between the anvil jaw and sealing jaw of each sealing mechanismas each sealing mechanism passes the predetermined location to form aclamped package; sealing the transversely clamped tube in the clampedarea to form a seal and a sealed package; severing the tube through theclamped seal area; and compressing the sealed package against aplurality of flanges extending from the adjacent sealing mechanismsthereby preforming the sealed package.
 18. The method of claim 17wherein severing the transversely clamped seal area further comprisesextending a serrated knife from a housing in the anvil jaw through theseal area into a corresponding receptacle in the sealing jaw.
 19. Themethod of claim 17 further comprising controlling the volume of productin the tube to be clamped by controlling the configuration of the tubeas each sealing mechanism closes so that the volume of product in eachclamped package is substantially the same.
 20. The method of claim 19wherein controlling the volume of product further comprises configuringthe angular orientation of the sealing mechanism as it closes at thepredetermined location to control the relative volume of product in eachpackage.
 21. The method of claim 19 wherein controlling the volume ofproduct further comprises contacting the tube with a member at alocation below where each sealing mechanism closes and above thepreceding closed sealing mechanism to adjust the configuration of thetube and thereby control the volume of product in the tube as eachsealing mechanism closes.
 22. The method of claim 21 wherein contactingthe tube with a member further comprises contacting the tube with a pairof opposing fingers which contact opposite sides of the tubesubstantially simultaneously, the fingers having opposing reciprocatingmovement.
 23. The method of claim 19 wherein controlling the volume ofproduct further comprises:contacting the tube with a first boundarysurface, contacting the tube on an opposing side with a second boundarysurface, the first and second boundary surfaces providing apredetermined tube configuration to control the volume of product in thetube; and closing a sealing mechanism after the tube has been given thepredetermined tube configuration to clamp the tube transversely to fixthe volume of product clamped in the tube.
 24. The method of claim 23wherein each sealing mechanism has a first boundary surface on one ofthe sealing or anvil jaws and a second boundary surface on the other ofthe sealing or anvil jaws and contacting the tube furthercomprises:contacting the tube with a first boundary surface on one ofthe sealing or anvil jaws of a sealing mechanism, said first boundarysurface further comprising a flange extending from the jaw; andcontacting the tube with a second boundary surface on an adjacentsealing mechanism, said second boundary surface further comprising anextendable plate and a means for extending and maintaining the plateextended to contact the tube, wherein one of the sealing mechanisms isabout to clamp the tube transversely, the adjacent sealing mechanismbeing already clamped.
 25. The method of claim 23 wherein sealing thetransversely clamped tube further comprises:energizing a transverseinduction coil mounted in the sealing mechanism to generate anelectromagnetic field for a period of time; inducing a current in thepolyfoil tube proximate to the energized transverse induction coil andthe generated electromagnetic field to heat and fuse the tube together;and de-energizing the transverse induction coil so that the clampedheated and fused tube will cool and form a transverse seal.
 26. Themethod of claim 17 wherein compressing the sealed packages furthercomprises altering the relative orientation of the adjacent sealingmechanisms to compress a package against the plurality of flanges toconform the package into the configuration bounded by the flanges. 27.The method of claim 17 further comprising controlling the orientation ofthe sealing mechanisms by adjusting orientation of the jaw mountedtransversely to the tube about a jaw axis of rotation.
 28. The method ofclaim 27 wherein controlling the orientation further comprises:mountingone of the anvil or sealing jaws of the sealing mechanism in thestructure for rotation about an axis and providing that jaw with a leverarm and a first cam follower attached to the end of the first lever arm;and controlling the angular orientation of the sealing mechanism bycontrolling the location of the first cam follower relative to the jawaxis by passing the first cam follower through a corresponding first camgroove as the structure is advanced so that motion of the first camfollower relative to the jaw axis controls the orientation of thesealing mechanism.
 29. The method of claim 28 wherein controlling theangular orientation of the sealing mechanism furthercomprises:positioning the first cam follower in one of a first or secondpath segments in the first cam groove as the structure advances and thefirst cam follower follows the path of the first cam groove, passingfirst through the first path segment and thereafter through the secondpath segment, the first path segment being configured to place a sealingmechanism in an advanced angular orientation, the angular orientation ofthe sealing mechanism being the plane in which the sealing jaw and anviljaw move relative to each other, an advanced orientation being theoutermost portion of the sealing mechanism plane traveling in front ofwhere it would be if the plane extended through the axis of the rotatingwheel, the second path segment being configured to move the position ofthe first cam follower relative to the jaw axis to change theorientation of a sealing mechanism from an advanced to a retardedorientation, the retarded orientation being the outermost portion of thesealing mechanism plane traveling behind where it would be if the planeextended through the axis of the rotating wheel, the length andorientation of the first and second path segments being selected so thatthe first cam follower associated with the leading sealing mechanismrunning from the first to the second path segments changes the sealingmechanism orientation to a retarded orientation while the first camfollower associated with the trailing sealing mechanism running in thefirst path segment provides the trailing sealing mechanism with anadvanced orientation so that the package clamped between the adjacentsealing mechanisms is compressed against the flanges of the sealingmechanisms for a period of time sufficient to preform the package. 30.The method of claim 29 wherein closing the sealing mechanisms at apredetermined location further comprises:positioning the first camfollower in a third path segment corresponding to the predeterminedlocation prior in sequence to the first path segment, the third pathsegment being configured with a movable cam segment having a pluralityof positions between a front position and a rear position including anominal position between the front and rear positions, the frontposition causing the first cam follower to be positioned so that thesealing mechanism is in one of a predetermined relative maximum advanceor relative maximum retard in angular orientation, the rear positioncorresponding to the other of the relative maximum advance or retard inangular orientation, and the nominal position corresponding to thenominal clamping position; determining whether the orientation of thenext sealing mechanism to be closed must be advanced or retardedrelative to the angular orientation of the preceding sealing mechanism;and moving the movable cam in the third path segment to the position inthe third path segment thereby providing the sealing mechanism with thedetermined angular orientation so that the closing of the sealingmechanism occur with the desired volume of product within the clampedtube.
 31. The method of claim 17 wherein the opening and closing of asealing mechanism further comprises:positioning a cam follower in a camgroove of a cam, the cam groove having a path configured to move the camfollower relative to the fixed point; connecting the cam follower to thepivot connecting the anvil and sealing jaws using a linked pushrod andlever arm mechanism; and moving the cam follower relative to the fixedpoint as the sealing mechanism advances so that relative motion of thecam follower actuates the linked pushrod and lever arm mechanism tooperate the hinge to close the anvil jaw and sealing jaw at thepredetermined location and to open the anvil jaw and sealing jaw at asecond predetermined location after the package has been sealed,pre-bent, and severed.
 32. Apparatus for controlling the orientation ofsealing mechanisms for use in a machine for forming a plurality ofsealed packages from an advancing tube filled with a product having aplurality of sealing mechanisms mounted in a spaced apart relationshipabout the periphery of a structure adapted for rotation about an axis ata controllable speed, adjacent leading and trailing sealing mechanismsbeing capable of tranversely clamping a length of product filled tubetherebetween, comprising:means for mounting each sealing mechanism inthe structure adapted for rotation about a first axis, the sealingmechanism having a nominal angular orientation wherein a sealingmechanism plane passes through the transversely clamped tube at anominal angle to a plane passing through the first axis and the axis ofthe rotating wheel; a lever arm secured to each sealing mechanism; afirst fixed cam having a first cam groove mounted in the machine; afirst cam follower secured to the end of each lever arm and adapted forrunning in the first cam groove so that for each sealing mechanism, thelocation of the first cam follower relative to the first axis, asdetermined by the first cam groove configuration, determines angularorientation of the sealing mechanism.
 33. The apparatus of claim 32 foruse in preforming packages wherein the first cam groove furthercomprises first and second path segments in the first cam forpositioning the first cam followers in preselected locations and thesealing mechanisms in corresponding preselected orientations relative tothe first axis, the first path segment being configured to place asealing mechanism in the nominal angular orientation being an advancedorientation with the outermost portion of the sealing mechanism planetraveling in front of where it would be if the sealing mechanism planewere in a radial orientation, the second path segment being configuredto change the position of one of the first cam followers relative to thefirst axis as the first cam advances along the second path to change theorientation of the corresponding sealing mechanism from an advanced to aretarded orientation, the retarded orientation being the outermostportion of the sealing mechanism plane traveling behind where it wouldbe if the sealing mechanism plane were in a radial orientation, thelength and orientation of the first and second path segments beingselected so that the first cam follower associated with the leadingsealing mechanism running from the first to the second path segmentschanges the sealing mechanism orientation to a retarded orientationwhile the first cam follower associated with the trailing sealingmechanism running in the first path segment provides the trailingsealing mechanism with an advanced orientation so that the sealedpackage clamped between the adjacent sealing mechanisms is compressedfor a period of time sufficient to preform the package.
 34. Theapparatus of claim 33 wherein the first cam groove further comprises:athird path segment disposed prior in sequence to the first path segment;a movable cam segment located in the third path segment having aplurality of positions between a front position and a rear position,including a nominal position between the front and rear positions, thefront position corresponding to one of a predetermined maximum advanceor maximum retard in angular orientation, the rear position of themovable cam segment corresponding to the other of the maximum advance orretard in orientation, the nominal position corresponding to the nominalangular orientation of the sealing mechanism; and means for moving themovable cam segment to one of the plurality of locations to configurethe third path segment to control the angular orientation of the sealingmechanism as it closes about and transversely clamps the tube.
 35. Theapparatus of claim 33 wherein the sealing mechanism further comprise aplurality of flanges oriented so that when the leading sealing mechanismis in a retarded orientation and the trailing sealing mechanism is anadvanced orientation the transversely clamped tube section is preformedsubstantially into the configuration bounded by the flanges.
 36. Theapparatus of claim 34 wherein the volume bounded by the flanges is about97% of the final volume for the configuration of a finished package.